1. Field of the Invention
The present invention relates to a device for driving a robot hand, which is adapted to automatically feed and supply objects via a robot or a pneumatic feeding device used in industrial automation equipment or semi-automation equipment. In particular, the present invention relates to a bi-directional feeding gripper device which is capable of performing a bi-directional movement including a vertical movement and a picking, by the operation of a single cylinder.
2. Description of the Prior Art
Generally, industrial automation equipment or semi-automation equipment include a robot adapted to feed, supply or insert continuously or repeatedly objects by using a pneumatic device. The pneumatic device involves basic operations including a movement that the pneumatic device reaches the position of the object and a movement for picking the object. Otherwise, the pneumatic device may involve a combination of two separated stepwise operations including a feeding operation wherein a gripped object is moved to a predetermined position and a placing operation wherein the object is placed on the predetermined position.
A typical example of such a conventional pneumatic device is a chucking gripper equipped with a feeding cylinder. The construction is illustrated in FIG. 1. As shown in the drawing, the pneumatic device includes a lifting cylinder 31 in which a piston is disposed, a chucking cylinder 33 coupled to the lower end of a driving rod 32 protruded downwardly through the lifting cylinder 31, and a chucking gripper 35 mounted to the chucking cylinder 33 and provided at its lower end with fingers 34.
As the lifting cylinder 31 drives, the chucking gripper 35 moves downwardly or upwardly. Irrespective of the driving of lifting cylinder 31, the fingers 34 of the chucking gripper 35 are driven by the chucking cylinder 33, so as to carry out operations of gripping or placing an object.
For accomplishing such separated two stepwise operations, this conventional pneumatic device requires two cylinders, as above-mentioned. It is also required to provide additional elements such as solenoids for driving the cylinders. As a result, the overall construction of the pneumatic device is complicated. Furthermore, there is a disadvantage of the delay in the operation time and the reduction in the accuracy of work, due to the two stepwise operations.